I am using Arc 10.2.2 and trying to populate the Strahler order field using the Arc Hydro Tools. I have downloaded the latest Arc Hydro Tools (ArcHydroTools 10.2.0.198.msi) and can't seem to get the Find Next Downstream Line to function properly. The Hydro ID is populated, the From and To Node fields are populated, but when I run the Find Next Downstream Line it doesn't populate the NextDownID field? It creates the field but the value is <Null> for all features. Also it gives no errors and actually says it has completed successfully in the Results window. Any ideas on how to fix this? I have tested this on 2 different databases with same results.